Viscoelasticity

Abstract Viscoelastic materials, which combine viscous and elastic characteristics, are abundant in the body. The theory of viscoelasticity is widely used to describe their response to mechanical loading, for both physiological and injurious levels of loading. Most viscoelastic materials are nonlinearly viscoelastic for strains of practical interest. This requires the use of nonlinear viscoelastic theories, of which quasi‐linear viscoelasticity is the most common. Structural viscoelastic models, which attempt to replicate the multiphase structure of soft biological tissues, have also been developed and are increasing in flexibility and complexity to better match the observed mechanical behavior of soft tissues. Future challenges in viscoelastic modeling of human body tissues include determiningin vivoproperties and developing computationally efficient models that can still capture the complex nonlinear viscoelastic behavior of these tissues.